Dallas Cowboys running back Ezekiel Elliott was suspended for six games Friday after a yearlong NFL investigation of his domestic violence case in Ohio.

The 2016 NFL rushing leader was suspended despite prosecutors in Columbus, Ohio, deciding a year ago not to pursue the case involving Elliott's girlfriend at the time in the same city where he starred for Ohio State.

The league, however, said there was "substantial and persuasive evidence" that Elliott had physical confrontations last summer with his then-girlfriend, Tiffany Thompson. Elliott will be eligible to return to the active roster on Oct. 23. His first possible game will be Week 8 at Washington.

Elliott, who turned 22 last month, has three days to appeal the ruling. One of his agents didn't immediately respond to a request for comment. The NFL Players Association said it was reviewing the decision and had been in touch with Elliott's representatives to consider his options.

The ruling requires Elliott to get an evaluation to determine whether he needs counseling or treatment, and to show proof that he is following up on any recommendations that are made.

The league revised its personal conduct policy in 2014 following sharp criticism of a case involving former Baltimore running back Ray Rice. The policy gave Commissioner Roger Goodell authority to suspend players for at least six games in domestic cases, with or without a conviction.

In a letter to Elliott informing him of the league's decision, NFL special counsel for conduct Todd Jones said advisers brought in by the league "were of the view that there is substantial and persuasive evidence supporting a finding that (Elliott) engaged in physical violence against Ms. Thompson on multiple occasions during the week of July 16, 2016."

Last September, the office of Columbus City Attorney Richard Pfeiffer cited conflicting and inconsistent information in the evidence in deciding against criminal charges.

The NFL's letter to Elliott cited the Ohio case and an incident this past spring when Elliott was caught on video pulling down a woman's shirt while watching a St. Patrick's Day parade in Dallas.

The decision came despite Cowboys owner Jerry Jones saying he hadn't seen anything to indicate Elliott was guilty of domestic violence and that he didn't think his star back would be suspended. Jones made the comments several times, including during festivities last weekend when he was inducted into the Pro Football Hall of Fame.

Elliott has had a string of off-field issues in the year since the Cowboys made him the fourth overall pick in the 2016 draft. He was seen in a legal marijuana shop during the preseason in Seattle last year and was also involved in a bar fight in Dallas a week before training camp this year.

The All-Pro back finished with 1,631 yards rushing in helping the Cowboys to the best record in the NFC at 13-3 before a divisional playoff loss to Green Bay. He set rookie franchise records for yards, rushing touchdowns (15) and total touchdowns (16).